Leinster made it seven wins from seven in their first block of United Rugby Championship fixtures by beating the Scarlets 35-5 in Llanelli.
Both sides were severely under-strength ahead of the autumn internationals, but the Irish had greater reserve depth to score five tries to one.
Chris Cosgrave, Rob Russell and Tom Clarkson were all on the scoresheet, while there were also two penalty try awards and Ross Byrne added three conversions.
A try from Steff Evans was the Scarlets’ sole response.
It took Leinster only 40 seconds to open the scoring. The Scarlets bungled the kick-off to give their opponents a line-out from where they moved the ball wide for Cosgrave to race over.
That was the only score of an otherwise featureless first quarter before the Scarlets sprung to life with an excellent try.
Ryan Conbeer, on his 50th appearance for the region, ran strongly down the left wing and, when the ball was recycled, a long pass from Jonathan Davies gave Evans the chance to outflank the cover defence.
Leinster quickly responded with their second try. Russell kicked ahead for Conbeer and Leinster hooker John McKee to contest possession and, when the ball ran free, Russell was on hand to score.
Byrne succeeded with his second touchline conversion to give his side a deserved 14-5 interval lead after giving the Scarlets a lesson in taking chances.
Seven minutes after the restart, the Irish province scored their third when Clarkson finished off a succession of forward drives.
Leinster became increasingly dominant and their cause was greatly helped when the Scarlets picked up two yellow cards in quick succession.
First to go was Dan Jones for repeated team infringements, quickly followed by Johnny McNicholl for a deliberate knock-on, which resulted in a penalty try award.
Playing with 13, the Scarlets had one of their best periods of the game and were aided by a yellow card for Leinster replacement prop Michael Milne.
However, the visitors illustrated their dominance by picking up a second penalty try, with Gareth Davies becoming the third Scarlet to be sin-binned.
